The Experts below are selected from a list of 11040 Experts worldwide ranked by ideXlab platform

Zhenhong Yuan - One of the best experts on this subject based on the ideXlab platform.

  • The Ways of Factors Influencing High-Solid Enzymatic Hydrolysis of Sugarcane Bagasse Treated by Liquid Hot Water
    ChemistrySelect, 2017
    Co-Authors: Wen Wang, Xinshu Zhuang, Qiong Wang, Xuesong Tan, Zhenhong Yuan
    Abstract:

    The influence ways of structural feature, hydrolytic viscosity and monosaccharides′ concentrations on the enzymatic hydrolysis of high-solid Liquid Hot Water (LHW)-treated lignocellulose were evaluated. The SEM observation showed that the residual lignin in the LHW-treated sugarcane bagasse (SCB) played an important role in gluing fasciculate structures, and XRD detection indicated the decrease of crystalline index (CrI) of LHW-treated SCB after lignin removal. The enzymatic hydrolysis of LHW-treated SCB with and without lignin removal showed that the residual lignin might block the access of cellobiohydrolase to the crystalline cellulose. The fractal kinetic model indicated that the benefit of the low viscosity for high-solid enzymatic hydrolysis of LHW-treated SCB would appear with the time going. As the enzymatic hydrolysis proceeding, the accumulation of glucose imposed more and more intense inhibition on the cellulolytic hydrolysis, while the xylose showed a little inhibition. The changes of UV spectra indicated that the glucose accumulation hardly affected the side chains containing tyrosine (Try) and/or tryptophan (Trp) which should be not in the catalytic active center of cellulase.

  • Microalgae pretreatment with Liquid Hot Water to enhance enzymatic hydrolysis efficiency.
    Bioresource technology, 2016
    Co-Authors: Tao Yuan, Shiyuan Xiao, Ying Guo, Weizheng Zhou, Zhenhong Yuan
    Abstract:

    Nowadays, microalgae are being considered as promising raw material for bioethanol production. In this work, three process variables during Liquid Hot Water (LHW) pretreatment prior to enzymatic hydrolysis by response surface methodology on Scenedesmus sp. WZKMT were investigated to enhance glucose recovery. Results indicated that the order of significance for three parameters was temperature>solid-to-Liquid ratio>time. The optimal condition was 1:13 (w/v), 147°C and 40min. The concentration and recovery of glucose under this condition were 14.223g·L(-1) and 89.32%, respectively, which were up to 5-fold higher than the samples without LHW pretreatment. In addition, the surface morphologies of microalgae cells before and after LHW pretreatment were also verified using scanning electron microscopy (SEM). LHW pretreatment can greatly enhance the enzymatic efficiency, and can be regarded as an ideal pretreatment method for glucose recovery from microalgae.

  • Structural Changes of Lignin after Liquid Hot Water Pretreatment and Its Effect on the Enzymatic Hydrolysis
    BioMed research international, 2016
    Co-Authors: Wen Wang, Xinshu Zhuang, Zhenhong Yuan, Qiong Wang
    Abstract:

    During Liquid Hot Water (LHW) pretreatment, lignin is mostly retained in the pretreated biomass, and the changes in the chemical and structural characteristics of lignin should probably refer to re-/depolymerization, solubilization, or glass transition. The residual lignin could influence the effective enzymatic hydrolysis of cellulose. The pure lignin was used to evaluate the effect of LHW process on its structural and chemical features. The surface morphology of LHW-treated lignin observed with the scanning electron microscopy (SEM) was more porous and irregular than that of untreated lignin. Compared to the untreated lignin, the surface area, total pore volume, and average pore size of LHW-treated lignin tested with the Brunner-Emmet-Teller (BET) measurement were increased. FTIR analysis showed that the chemical structure of lignin was broken down in the LHW process. Additionally, the impact of untreated and treated lignin on the enzymatic hydrolysis of cellulose was also explored. The LHW-treated lignin had little impact on the cellulase adsorption and enzyme activities and somehow could improve the enzymatic hydrolysis of cellulose.

  • Liquid Hot Water pretreatment of lignocellulosic biomass for bioethanol production accompanying with high valuable products
    Bioresource Technology, 2016
    Co-Authors: Xinshu Zhuang, Qiang Yu, Wen Wang, Wei Qi, Qiong Wang, Guixiong Zhou, Zhenhong Yuan
    Abstract:

    Pretreatment is an essential prerequisite to overcome recalcitrance of biomass and enhance the ethanol conversion efficiency of polysaccharides. Compared with other pretreatment methods, Liquid Hot Water (LHW) pretreatment not only reduces the downstream pressure by making cellulose more accessible to the enzymes but minimizes the formation of degradation products that inhibit the growth of fermentative microorganisms. Herein, this review summarized the improved LHW process for different biomass feedstocks, the decomposition behavior of biomass in the LHW process, the enzymatic hydrolysis of LHW-treated substrates, and production of high value-added products and ethanol. Moreover, a combined process producing ethanol and high value-added products was proposed basing on the works of Guangzhou Institute of Energy Conversion to make LHW pretreatment acceptable in the biorefinery of cellulosic ethanol.

  • Influence of lignin level on release of hemicellulose-derived sugars in Liquid Hot Water.
    International journal of biological macromolecules, 2015
    Co-Authors: Xinshu Zhuang, Wen Wang, Qiong Wang, Zhenhong Yuan, Xiaoying Kong, Xuesong Tan
    Abstract:

    Lignin layers surrounding hemicelluloses and cellulose in the plant cell walls protect them from deconstruction. This recalcitrance to sugar release is a major limitation for cost-effective industrial conversion of lignocellulosic biomass to biofuels. Many literatures had reported the contribution of lignin removal to cellulose accessibility to enzyme, but less to the hemicellulose hydrolysis. Herein, beech xylan with lignin addition, partly delignified sugarcane bagasse (SB), energy sorghum hybrids (ESH) were treated in Liquid Hot Water (LHW) to investigate the effect of lignin on hemicellulose decomposition. The addition of lignin can enhance the low degree of polymerization of xylooligomers production resulted from the acid catalyzed cleavage of lignin-derived acidic products. However, a negative correlation was observed initially between the lignin level and the total xylose yield from ESH. Furthermore, samples with lignin addition or high lignin content had a great resistant to harsh reaction environment, about 93.5% total xylose lost but only 52.3% released due to the lack of lignin protection for the sample with 100% lignin removal.

Xuesong Tan - One of the best experts on this subject based on the ideXlab platform.

  • The Ways of Factors Influencing High-Solid Enzymatic Hydrolysis of Sugarcane Bagasse Treated by Liquid Hot Water
    ChemistrySelect, 2017
    Co-Authors: Wen Wang, Xinshu Zhuang, Qiong Wang, Xuesong Tan, Zhenhong Yuan
    Abstract:

    The influence ways of structural feature, hydrolytic viscosity and monosaccharides′ concentrations on the enzymatic hydrolysis of high-solid Liquid Hot Water (LHW)-treated lignocellulose were evaluated. The SEM observation showed that the residual lignin in the LHW-treated sugarcane bagasse (SCB) played an important role in gluing fasciculate structures, and XRD detection indicated the decrease of crystalline index (CrI) of LHW-treated SCB after lignin removal. The enzymatic hydrolysis of LHW-treated SCB with and without lignin removal showed that the residual lignin might block the access of cellobiohydrolase to the crystalline cellulose. The fractal kinetic model indicated that the benefit of the low viscosity for high-solid enzymatic hydrolysis of LHW-treated SCB would appear with the time going. As the enzymatic hydrolysis proceeding, the accumulation of glucose imposed more and more intense inhibition on the cellulolytic hydrolysis, while the xylose showed a little inhibition. The changes of UV spectra indicated that the glucose accumulation hardly affected the side chains containing tyrosine (Try) and/or tryptophan (Trp) which should be not in the catalytic active center of cellulase.

  • Influence of lignin level on release of hemicellulose-derived sugars in Liquid Hot Water.
    International journal of biological macromolecules, 2015
    Co-Authors: Xinshu Zhuang, Wen Wang, Qiong Wang, Zhenhong Yuan, Xiaoying Kong, Xuesong Tan
    Abstract:

    Lignin layers surrounding hemicelluloses and cellulose in the plant cell walls protect them from deconstruction. This recalcitrance to sugar release is a major limitation for cost-effective industrial conversion of lignocellulosic biomass to biofuels. Many literatures had reported the contribution of lignin removal to cellulose accessibility to enzyme, but less to the hemicellulose hydrolysis. Herein, beech xylan with lignin addition, partly delignified sugarcane bagasse (SB), energy sorghum hybrids (ESH) were treated in Liquid Hot Water (LHW) to investigate the effect of lignin on hemicellulose decomposition. The addition of lignin can enhance the low degree of polymerization of xylooligomers production resulted from the acid catalyzed cleavage of lignin-derived acidic products. However, a negative correlation was observed initially between the lignin level and the total xylose yield from ESH. Furthermore, samples with lignin addition or high lignin content had a great resistant to harsh reaction environment, about 93.5% total xylose lost but only 52.3% released due to the lack of lignin protection for the sample with 100% lignin removal.

  • Liquid Hot Water pretreatment of energy grasses and its influence of physico-chemical changes on enzymatic digestibility.
    Bioresource technology, 2015
    Co-Authors: Jing Liu, Xinshu Zhuang, Wen Wang, Qiong Wang, Zhenhong Yuan, Xuesong Tan, Xiaoying Kong
    Abstract:

    Pennisetum hybrid I, II and switchgrass were pretreated with Liquid Hot Water to enhance the release of sugars. The optimum hydrolysis factor for three energy grasses was 5.98, and the total xylose yield was 88.4%, 98.1% and 83.6% for grass I, II and S. It was indicated that the ratio of syringyl and guaiacyl units of lignin played an important role on the hemicellulose hydrolysis in LHW than branch degree, but latter contributed more on the characterization of xylooligomers degree of polymerization. Moreover, the analysis of multi-scale changes of substrate suggested that cellulose crystallinity index and degree of polymerization seemed no direct relationships for increase of enzymatic digestibility. While lignin barrier was the main factor limiting efficiency of sugar release, and Pennisetum hybrid with low lignin content and high sugar recovery was proved to be a prospective plant feedstock for cellulosic ethanol production.

  • pretreatment of sugarcane bagasse with Liquid Hot Water and aqueous ammonia
    Bioresource Technology, 2013
    Co-Authors: Xinshu Zhuang, Wen Wang, Qiong Wang, Zhenhong Yuan, Xuesong Tan
    Abstract:

    Abstract Low Water consumption operation (LWCO) can reduce the usage of Water and energy input for the Liquid Hot Water (LHW) pretreatment of sugarcane bagasse (SB) but causes great negative effects on the saccharification rate of xylose and enzymatic digestibility (ED) of cellulose. Therefore, a combined pretreatment with LHW and aqueous ammonia (LHWAA) was developed. ED of glucan and xylan is enhanced greatly resulted from the removal of hemicellulose and lignin after the LHWAA pretreatment. However, the intriguing results of low lignin removal and ED value were observed at the high reaction temperature of 180 °C for the second step pretreatment of AA. It was proposed that lignin or pseudo-lignin droplet redeposited on the surface of residual solids might play a crucial role in determining the ED, so it is indispensable to make the enzyme access to the cellulose by the step of post-treatment with ultrasonic washing or Hot washing. Coupled with the process of post-treatment and enzymatic hydrolysis, a high hemicellulose derived sugars recovery of 75.5% and glucose recovery of 87% was obtained for LHWAA pretreatment.

  • hydrolysis of sweet sorghum bagasse and eucalyptus wood chips with Liquid Hot Water
    Bioresource Technology, 2012
    Co-Authors: Xinshu Zhuang, Qiong Wang, Xuesong Tan, Zhenhong Yuan
    Abstract:

    The chemical composition, hydrolysis products, and kinetics during Liquid Hot Water pretreatment of sweet sorghum bagasse (SSB) and eucalyptus wood chips (EWC) were investigated. Under optimal conditions, a total xylose recovery of 79.6% and 55.6% for SSB and of 74.9% and 84.4% for EWC was achieved after pretreatments in a step-change flow rate reactor (184 °C, 20 ml/min, 8 min, and 10 ml/min, 10 min) and batch stirred reactor (184 °C, 5%w/v, 18 min), respectively. More than 90% of the xylose was recovered as oligomers from SSB, independent of the type of reactor employed. The activation energies of xylan decomposition of SSB in the step-change flow rate reactor was 6.5-fold greater than that of EWC in the batch stirred reactor due to accumulation of acidic products. These findings show that sugar recovery is dependent on the reactor configuration for specific substrates.

Xinshu Zhuang - One of the best experts on this subject based on the ideXlab platform.

  • The Ways of Factors Influencing High-Solid Enzymatic Hydrolysis of Sugarcane Bagasse Treated by Liquid Hot Water
    ChemistrySelect, 2017
    Co-Authors: Wen Wang, Xinshu Zhuang, Qiong Wang, Xuesong Tan, Zhenhong Yuan
    Abstract:

    The influence ways of structural feature, hydrolytic viscosity and monosaccharides′ concentrations on the enzymatic hydrolysis of high-solid Liquid Hot Water (LHW)-treated lignocellulose were evaluated. The SEM observation showed that the residual lignin in the LHW-treated sugarcane bagasse (SCB) played an important role in gluing fasciculate structures, and XRD detection indicated the decrease of crystalline index (CrI) of LHW-treated SCB after lignin removal. The enzymatic hydrolysis of LHW-treated SCB with and without lignin removal showed that the residual lignin might block the access of cellobiohydrolase to the crystalline cellulose. The fractal kinetic model indicated that the benefit of the low viscosity for high-solid enzymatic hydrolysis of LHW-treated SCB would appear with the time going. As the enzymatic hydrolysis proceeding, the accumulation of glucose imposed more and more intense inhibition on the cellulolytic hydrolysis, while the xylose showed a little inhibition. The changes of UV spectra indicated that the glucose accumulation hardly affected the side chains containing tyrosine (Try) and/or tryptophan (Trp) which should be not in the catalytic active center of cellulase.

  • Structural Changes of Lignin after Liquid Hot Water Pretreatment and Its Effect on the Enzymatic Hydrolysis
    BioMed research international, 2016
    Co-Authors: Wen Wang, Xinshu Zhuang, Zhenhong Yuan, Qiong Wang
    Abstract:

    During Liquid Hot Water (LHW) pretreatment, lignin is mostly retained in the pretreated biomass, and the changes in the chemical and structural characteristics of lignin should probably refer to re-/depolymerization, solubilization, or glass transition. The residual lignin could influence the effective enzymatic hydrolysis of cellulose. The pure lignin was used to evaluate the effect of LHW process on its structural and chemical features. The surface morphology of LHW-treated lignin observed with the scanning electron microscopy (SEM) was more porous and irregular than that of untreated lignin. Compared to the untreated lignin, the surface area, total pore volume, and average pore size of LHW-treated lignin tested with the Brunner-Emmet-Teller (BET) measurement were increased. FTIR analysis showed that the chemical structure of lignin was broken down in the LHW process. Additionally, the impact of untreated and treated lignin on the enzymatic hydrolysis of cellulose was also explored. The LHW-treated lignin had little impact on the cellulase adsorption and enzyme activities and somehow could improve the enzymatic hydrolysis of cellulose.

  • Liquid Hot Water pretreatment of lignocellulosic biomass for bioethanol production accompanying with high valuable products
    Bioresource Technology, 2016
    Co-Authors: Xinshu Zhuang, Qiang Yu, Wen Wang, Wei Qi, Qiong Wang, Guixiong Zhou, Zhenhong Yuan
    Abstract:

    Pretreatment is an essential prerequisite to overcome recalcitrance of biomass and enhance the ethanol conversion efficiency of polysaccharides. Compared with other pretreatment methods, Liquid Hot Water (LHW) pretreatment not only reduces the downstream pressure by making cellulose more accessible to the enzymes but minimizes the formation of degradation products that inhibit the growth of fermentative microorganisms. Herein, this review summarized the improved LHW process for different biomass feedstocks, the decomposition behavior of biomass in the LHW process, the enzymatic hydrolysis of LHW-treated substrates, and production of high value-added products and ethanol. Moreover, a combined process producing ethanol and high value-added products was proposed basing on the works of Guangzhou Institute of Energy Conversion to make LHW pretreatment acceptable in the biorefinery of cellulosic ethanol.

  • Influence of lignin level on release of hemicellulose-derived sugars in Liquid Hot Water.
    International journal of biological macromolecules, 2015
    Co-Authors: Xinshu Zhuang, Wen Wang, Qiong Wang, Zhenhong Yuan, Xiaoying Kong, Xuesong Tan
    Abstract:

    Lignin layers surrounding hemicelluloses and cellulose in the plant cell walls protect them from deconstruction. This recalcitrance to sugar release is a major limitation for cost-effective industrial conversion of lignocellulosic biomass to biofuels. Many literatures had reported the contribution of lignin removal to cellulose accessibility to enzyme, but less to the hemicellulose hydrolysis. Herein, beech xylan with lignin addition, partly delignified sugarcane bagasse (SB), energy sorghum hybrids (ESH) were treated in Liquid Hot Water (LHW) to investigate the effect of lignin on hemicellulose decomposition. The addition of lignin can enhance the low degree of polymerization of xylooligomers production resulted from the acid catalyzed cleavage of lignin-derived acidic products. However, a negative correlation was observed initially between the lignin level and the total xylose yield from ESH. Furthermore, samples with lignin addition or high lignin content had a great resistant to harsh reaction environment, about 93.5% total xylose lost but only 52.3% released due to the lack of lignin protection for the sample with 100% lignin removal.

  • Liquid Hot Water pretreatment of energy grasses and its influence of physico-chemical changes on enzymatic digestibility.
    Bioresource technology, 2015
    Co-Authors: Jing Liu, Xinshu Zhuang, Wen Wang, Qiong Wang, Zhenhong Yuan, Xuesong Tan, Xiaoying Kong
    Abstract:

    Pennisetum hybrid I, II and switchgrass were pretreated with Liquid Hot Water to enhance the release of sugars. The optimum hydrolysis factor for three energy grasses was 5.98, and the total xylose yield was 88.4%, 98.1% and 83.6% for grass I, II and S. It was indicated that the ratio of syringyl and guaiacyl units of lignin played an important role on the hemicellulose hydrolysis in LHW than branch degree, but latter contributed more on the characterization of xylooligomers degree of polymerization. Moreover, the analysis of multi-scale changes of substrate suggested that cellulose crystallinity index and degree of polymerization seemed no direct relationships for increase of enzymatic digestibility. While lignin barrier was the main factor limiting efficiency of sugar release, and Pennisetum hybrid with low lignin content and high sugar recovery was proved to be a prospective plant feedstock for cellulosic ethanol production.

Qiong Wang - One of the best experts on this subject based on the ideXlab platform.

  • The Ways of Factors Influencing High-Solid Enzymatic Hydrolysis of Sugarcane Bagasse Treated by Liquid Hot Water
    ChemistrySelect, 2017
    Co-Authors: Wen Wang, Xinshu Zhuang, Qiong Wang, Xuesong Tan, Zhenhong Yuan
    Abstract:

    The influence ways of structural feature, hydrolytic viscosity and monosaccharides′ concentrations on the enzymatic hydrolysis of high-solid Liquid Hot Water (LHW)-treated lignocellulose were evaluated. The SEM observation showed that the residual lignin in the LHW-treated sugarcane bagasse (SCB) played an important role in gluing fasciculate structures, and XRD detection indicated the decrease of crystalline index (CrI) of LHW-treated SCB after lignin removal. The enzymatic hydrolysis of LHW-treated SCB with and without lignin removal showed that the residual lignin might block the access of cellobiohydrolase to the crystalline cellulose. The fractal kinetic model indicated that the benefit of the low viscosity for high-solid enzymatic hydrolysis of LHW-treated SCB would appear with the time going. As the enzymatic hydrolysis proceeding, the accumulation of glucose imposed more and more intense inhibition on the cellulolytic hydrolysis, while the xylose showed a little inhibition. The changes of UV spectra indicated that the glucose accumulation hardly affected the side chains containing tyrosine (Try) and/or tryptophan (Trp) which should be not in the catalytic active center of cellulase.

  • Structural Changes of Lignin after Liquid Hot Water Pretreatment and Its Effect on the Enzymatic Hydrolysis
    BioMed research international, 2016
    Co-Authors: Wen Wang, Xinshu Zhuang, Zhenhong Yuan, Qiong Wang
    Abstract:

    During Liquid Hot Water (LHW) pretreatment, lignin is mostly retained in the pretreated biomass, and the changes in the chemical and structural characteristics of lignin should probably refer to re-/depolymerization, solubilization, or glass transition. The residual lignin could influence the effective enzymatic hydrolysis of cellulose. The pure lignin was used to evaluate the effect of LHW process on its structural and chemical features. The surface morphology of LHW-treated lignin observed with the scanning electron microscopy (SEM) was more porous and irregular than that of untreated lignin. Compared to the untreated lignin, the surface area, total pore volume, and average pore size of LHW-treated lignin tested with the Brunner-Emmet-Teller (BET) measurement were increased. FTIR analysis showed that the chemical structure of lignin was broken down in the LHW process. Additionally, the impact of untreated and treated lignin on the enzymatic hydrolysis of cellulose was also explored. The LHW-treated lignin had little impact on the cellulase adsorption and enzyme activities and somehow could improve the enzymatic hydrolysis of cellulose.

  • Liquid Hot Water pretreatment of lignocellulosic biomass for bioethanol production accompanying with high valuable products
    Bioresource Technology, 2016
    Co-Authors: Xinshu Zhuang, Qiang Yu, Wen Wang, Wei Qi, Qiong Wang, Guixiong Zhou, Zhenhong Yuan
    Abstract:

    Pretreatment is an essential prerequisite to overcome recalcitrance of biomass and enhance the ethanol conversion efficiency of polysaccharides. Compared with other pretreatment methods, Liquid Hot Water (LHW) pretreatment not only reduces the downstream pressure by making cellulose more accessible to the enzymes but minimizes the formation of degradation products that inhibit the growth of fermentative microorganisms. Herein, this review summarized the improved LHW process for different biomass feedstocks, the decomposition behavior of biomass in the LHW process, the enzymatic hydrolysis of LHW-treated substrates, and production of high value-added products and ethanol. Moreover, a combined process producing ethanol and high value-added products was proposed basing on the works of Guangzhou Institute of Energy Conversion to make LHW pretreatment acceptable in the biorefinery of cellulosic ethanol.

  • Influence of lignin level on release of hemicellulose-derived sugars in Liquid Hot Water.
    International journal of biological macromolecules, 2015
    Co-Authors: Xinshu Zhuang, Wen Wang, Qiong Wang, Zhenhong Yuan, Xiaoying Kong, Xuesong Tan
    Abstract:

    Lignin layers surrounding hemicelluloses and cellulose in the plant cell walls protect them from deconstruction. This recalcitrance to sugar release is a major limitation for cost-effective industrial conversion of lignocellulosic biomass to biofuels. Many literatures had reported the contribution of lignin removal to cellulose accessibility to enzyme, but less to the hemicellulose hydrolysis. Herein, beech xylan with lignin addition, partly delignified sugarcane bagasse (SB), energy sorghum hybrids (ESH) were treated in Liquid Hot Water (LHW) to investigate the effect of lignin on hemicellulose decomposition. The addition of lignin can enhance the low degree of polymerization of xylooligomers production resulted from the acid catalyzed cleavage of lignin-derived acidic products. However, a negative correlation was observed initially between the lignin level and the total xylose yield from ESH. Furthermore, samples with lignin addition or high lignin content had a great resistant to harsh reaction environment, about 93.5% total xylose lost but only 52.3% released due to the lack of lignin protection for the sample with 100% lignin removal.

  • Liquid Hot Water pretreatment of energy grasses and its influence of physico-chemical changes on enzymatic digestibility.
    Bioresource technology, 2015
    Co-Authors: Jing Liu, Xinshu Zhuang, Wen Wang, Qiong Wang, Zhenhong Yuan, Xuesong Tan, Xiaoying Kong
    Abstract:

    Pennisetum hybrid I, II and switchgrass were pretreated with Liquid Hot Water to enhance the release of sugars. The optimum hydrolysis factor for three energy grasses was 5.98, and the total xylose yield was 88.4%, 98.1% and 83.6% for grass I, II and S. It was indicated that the ratio of syringyl and guaiacyl units of lignin played an important role on the hemicellulose hydrolysis in LHW than branch degree, but latter contributed more on the characterization of xylooligomers degree of polymerization. Moreover, the analysis of multi-scale changes of substrate suggested that cellulose crystallinity index and degree of polymerization seemed no direct relationships for increase of enzymatic digestibility. While lignin barrier was the main factor limiting efficiency of sugar release, and Pennisetum hybrid with low lignin content and high sugar recovery was proved to be a prospective plant feedstock for cellulosic ethanol production.

Wen Wang - One of the best experts on this subject based on the ideXlab platform.

  • The Ways of Factors Influencing High-Solid Enzymatic Hydrolysis of Sugarcane Bagasse Treated by Liquid Hot Water
    ChemistrySelect, 2017
    Co-Authors: Wen Wang, Xinshu Zhuang, Qiong Wang, Xuesong Tan, Zhenhong Yuan
    Abstract:

    The influence ways of structural feature, hydrolytic viscosity and monosaccharides′ concentrations on the enzymatic hydrolysis of high-solid Liquid Hot Water (LHW)-treated lignocellulose were evaluated. The SEM observation showed that the residual lignin in the LHW-treated sugarcane bagasse (SCB) played an important role in gluing fasciculate structures, and XRD detection indicated the decrease of crystalline index (CrI) of LHW-treated SCB after lignin removal. The enzymatic hydrolysis of LHW-treated SCB with and without lignin removal showed that the residual lignin might block the access of cellobiohydrolase to the crystalline cellulose. The fractal kinetic model indicated that the benefit of the low viscosity for high-solid enzymatic hydrolysis of LHW-treated SCB would appear with the time going. As the enzymatic hydrolysis proceeding, the accumulation of glucose imposed more and more intense inhibition on the cellulolytic hydrolysis, while the xylose showed a little inhibition. The changes of UV spectra indicated that the glucose accumulation hardly affected the side chains containing tyrosine (Try) and/or tryptophan (Trp) which should be not in the catalytic active center of cellulase.

  • Structural Changes of Lignin after Liquid Hot Water Pretreatment and Its Effect on the Enzymatic Hydrolysis
    BioMed research international, 2016
    Co-Authors: Wen Wang, Xinshu Zhuang, Zhenhong Yuan, Qiong Wang
    Abstract:

    During Liquid Hot Water (LHW) pretreatment, lignin is mostly retained in the pretreated biomass, and the changes in the chemical and structural characteristics of lignin should probably refer to re-/depolymerization, solubilization, or glass transition. The residual lignin could influence the effective enzymatic hydrolysis of cellulose. The pure lignin was used to evaluate the effect of LHW process on its structural and chemical features. The surface morphology of LHW-treated lignin observed with the scanning electron microscopy (SEM) was more porous and irregular than that of untreated lignin. Compared to the untreated lignin, the surface area, total pore volume, and average pore size of LHW-treated lignin tested with the Brunner-Emmet-Teller (BET) measurement were increased. FTIR analysis showed that the chemical structure of lignin was broken down in the LHW process. Additionally, the impact of untreated and treated lignin on the enzymatic hydrolysis of cellulose was also explored. The LHW-treated lignin had little impact on the cellulase adsorption and enzyme activities and somehow could improve the enzymatic hydrolysis of cellulose.

  • Liquid Hot Water pretreatment of lignocellulosic biomass for bioethanol production accompanying with high valuable products
    Bioresource Technology, 2016
    Co-Authors: Xinshu Zhuang, Qiang Yu, Wen Wang, Wei Qi, Qiong Wang, Guixiong Zhou, Zhenhong Yuan
    Abstract:

    Pretreatment is an essential prerequisite to overcome recalcitrance of biomass and enhance the ethanol conversion efficiency of polysaccharides. Compared with other pretreatment methods, Liquid Hot Water (LHW) pretreatment not only reduces the downstream pressure by making cellulose more accessible to the enzymes but minimizes the formation of degradation products that inhibit the growth of fermentative microorganisms. Herein, this review summarized the improved LHW process for different biomass feedstocks, the decomposition behavior of biomass in the LHW process, the enzymatic hydrolysis of LHW-treated substrates, and production of high value-added products and ethanol. Moreover, a combined process producing ethanol and high value-added products was proposed basing on the works of Guangzhou Institute of Energy Conversion to make LHW pretreatment acceptable in the biorefinery of cellulosic ethanol.

  • Influence of lignin level on release of hemicellulose-derived sugars in Liquid Hot Water.
    International journal of biological macromolecules, 2015
    Co-Authors: Xinshu Zhuang, Wen Wang, Qiong Wang, Zhenhong Yuan, Xiaoying Kong, Xuesong Tan
    Abstract:

    Lignin layers surrounding hemicelluloses and cellulose in the plant cell walls protect them from deconstruction. This recalcitrance to sugar release is a major limitation for cost-effective industrial conversion of lignocellulosic biomass to biofuels. Many literatures had reported the contribution of lignin removal to cellulose accessibility to enzyme, but less to the hemicellulose hydrolysis. Herein, beech xylan with lignin addition, partly delignified sugarcane bagasse (SB), energy sorghum hybrids (ESH) were treated in Liquid Hot Water (LHW) to investigate the effect of lignin on hemicellulose decomposition. The addition of lignin can enhance the low degree of polymerization of xylooligomers production resulted from the acid catalyzed cleavage of lignin-derived acidic products. However, a negative correlation was observed initially between the lignin level and the total xylose yield from ESH. Furthermore, samples with lignin addition or high lignin content had a great resistant to harsh reaction environment, about 93.5% total xylose lost but only 52.3% released due to the lack of lignin protection for the sample with 100% lignin removal.

  • Liquid Hot Water pretreatment of energy grasses and its influence of physico-chemical changes on enzymatic digestibility.
    Bioresource technology, 2015
    Co-Authors: Jing Liu, Xinshu Zhuang, Wen Wang, Qiong Wang, Zhenhong Yuan, Xuesong Tan, Xiaoying Kong
    Abstract:

    Pennisetum hybrid I, II and switchgrass were pretreated with Liquid Hot Water to enhance the release of sugars. The optimum hydrolysis factor for three energy grasses was 5.98, and the total xylose yield was 88.4%, 98.1% and 83.6% for grass I, II and S. It was indicated that the ratio of syringyl and guaiacyl units of lignin played an important role on the hemicellulose hydrolysis in LHW than branch degree, but latter contributed more on the characterization of xylooligomers degree of polymerization. Moreover, the analysis of multi-scale changes of substrate suggested that cellulose crystallinity index and degree of polymerization seemed no direct relationships for increase of enzymatic digestibility. While lignin barrier was the main factor limiting efficiency of sugar release, and Pennisetum hybrid with low lignin content and high sugar recovery was proved to be a prospective plant feedstock for cellulosic ethanol production.